# BigQuery Sink Connector V2 fails on tombstone event with Avro and Upsert\_delete configs

**URL:** <https://forum.confluent.io/t/bigquery-sink-connector-v2-fails-on-tombstone-event-with-avro-and-upsert-delete-configs/38226>\
**Category:** Managed Connectors\
**Created:** [19 January 2026 15:11 UTC](https://forum.confluent.io/t/bigquery-sink-connector-v2-fails-on-tombstone-event-with-avro-and-upsert-delete-configs/38226 "2026-01-19T15:11:46Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![flaviuratiu](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.confluent.io/flaviuratiu/32/5225_2.png) [@flaviuratiu](https://forum.confluent.io/u/flaviuratiu)\
**Post date:** [19 January 2026 15:11 UTC](https://forum.confluent.io/t/bigquery-sink-connector-v2-fails-on-tombstone-event-with-avro-and-upsert-delete-configs/38226/1 "2026-01-19T15:11:46Z")

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I’m facing an issue with a BigQuery Sink Connector V2 having Ingestion Mode UPSERT\_DELETE and AVRO keys and values.

The following error is thrown when tombstone events are consumed:  
```  
Error encountered in task lcc-goz0v3-0. Executing stage ‘TASK\_PUT’ with class ‘org.apache.kafka.connect.sink.SinkTask’.  
Task ID  
task-0

io.confluent.connect.bigquerystorage.exception.ConversionConnectException: Top-level Kafka Connect schema must be of type ‘struct’  
at io.confluent.connect.bigquerystorage.convert.BigQueryRecordConverter.convertRecord(BigQueryRecordConverter.java:88)  
at io.confluent.connect.bigquerystorage.convert.BigQueryRecordConverter.getConvertedRecord(BigQueryRecordConverter.java:105)  
at io.confluent.connect.bigquerystorage.convert.BigQueryRecordConverter.getConvertedRecord(BigQueryRecordConverter.java:39)  
at io.confluent.connect.bigquerystorage.write.storageapi.StorageWriteApiWriter$Builder.convertRecord(StorageWriteApiWriter.java:144)  
at io.confluent.connect.bigquerystorage.write.storageapi.StorageWriteApiWriter$Builder.addRow(StorageWriteApiWriter.java:114)  
at io.confluent.connect.bigquerystorage.BigQueryStorageSinkTask.writeSinkRecords(BigQueryStorageSinkTask.java:283)  
at io.confluent.connect.bigquerystorage.BigQueryStorageSinkTask.put(BigQueryStorageSinkTask.java:332)  
at org.apache.kafka.connect.runtime.WorkerSinkTask.deliverMessages(WorkerSinkTask.java:753)  
at org.apache.kafka.connect.runtime.WorkerSinkTask.poll(WorkerSinkTask.java:379)  
at org.apache.kafka.connect.runtime.WorkerSinkTask.iteration(WorkerSinkTask.java:270)  
at org.apache.kafka.connect.runtime.WorkerSinkTask.execute(WorkerSinkTask.java:239)  
at org.apache.kafka.connect.runtime.WorkerTask.doRun(WorkerTask.java:272)  
at org.apache.kafka.connect.runtime.WorkerTask.run(WorkerTask.java:328)  
at org.apache.kafka.connect.runtime.isolation.Plugins.lambda$withClassLoader$7(Plugins.java:341)  
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:572)  
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)  
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)  
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)  
at java.base/java.lang.Thread.run(Thread.java:1583)  
```

If I use the same connector configuration but with Ingestion Mode BATCH LOADING, there are no errors.

Could you please advise how I can get the UPSERT\_DELETE mode to work with Avro messages?

Thank you!

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<div class="post-metadata">

**Author:** ![dtroiano](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.confluent.io/dtroiano/32/1961_2.png) [@dtroiano](https://forum.confluent.io/u/dtroiano)\
**Post date:** [20 February 2026 20:53 UTC](https://forum.confluent.io/t/bigquery-sink-connector-v2-fails-on-tombstone-event-with-avro-and-upsert-delete-configs/38226/4 "2026-02-20T20:53:14Z")

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Opened on 20 February 2026 20:53 UTC